Car Collector International
Supercar · 2004–2015

Mercedes-Benz SLK 55 AMG

The naturally aspirated AMG V8 SLK — folding-hardtop roadster with the M113 5.4-litre in the R171 and the M152 5.5-litre in the R172.

Roadster
Car Collector International Editorial
Mercedes-Benz SLK 55 AMG
OverviewVariants & SpecsCollector VariantsBuyer's GuideWhat to PayOwnershipCommon ProblemsValuationAuction ResultsInvestment OutlookRecommended Network
Overview

Why this car matters

Introduced in 2004 on the R171 platform, the SLK 55 AMG dropped AMG's hand-built 5.4-litre M113 naturally aspirated V8 into Mercedes-Benz's compact folding-hardtop roadster, producing 355 bhp driving the rear wheels through a 7G-Tronic seven-speed automatic. It sat between the supercharged SL 55 and the entry-level SLK 350 as AMG's first V8 SLK and remained in production through the 2008 facelift.

For the R172 generation launched in 2012, the SLK 55 AMG adopted the naturally aspirated 5.5-litre M152 V8 (a de-tuned, non-turbo derivative of the M157 architecture) producing 415 bhp, with cylinder deactivation and stop-start. The R172 was the last naturally aspirated AMG V8 SLK before the model was renamed SLC and the V8 option was withdrawn, ending production in 2015.

The only V8 SLKs — and the R172 5.5 M152 in particular is now recognised as the final naturally aspirated AMG V8 fitted to the compact roadster line before turbocharging and rebranding to SLC. R171 examples represent the closing chapter of the M113 V8 family across the range.

Variants

Range and production

VariantYearsProductionNotes
SLK 55 AMG (R171 pre-facelift)2004–2008—5.4L M113 naturally aspirated V8, 355 bhp; 7G-Tronic automatic; hand-built AMG engine with signed plaque. R171 combined production (Sept 2004–Sept 2011) stated as more than 9,500 units by Dr. Nils Beckmann (Mercedes-AMG) in documented forum correspondence.
SLK 55 AMG Black Series (R171)2006–2008—Fixed-roof, stripped, wide-arched track-focused derivative; 400 bhp, no folding roof, extensive body and suspension changes. Production: 120 units, confirmed via the Mercedes-Benz archive per Mercedes-AMG specialist Mechatronik; none sold in the North American market.
SLK 55 AMG (R171 facelift)2008–2011—Refreshed nose, revised interior; same 355 bhp M113 V8.
SLK 55 AMG (R172)2012–2015—5.5L M152 naturally aspirated V8, 415 bhp, cylinder deactivation, 7G-Tronic; the last naturally aspirated V8 SLK.
Collector Variants

Limited & special editions

The models below represent the most significant limited and special edition variants — factory-produced cars that command meaningful premiums over standard examples and warrant specific attention from serious collectors.

SLK 55 AMG Black Series (R171) · 2006–2008

120 units (2006–2008), confirmed via the Mercedes-Benz archive per Mercedes-AMG specialist Mechatronik; none sold in the North American market. Corroborated by Robb Report's Black Series ranking.
Distinguishing features
Track-focused derivative of the R171 SLK 55 AMG. Folding hardtop deleted in favour of a fixed carbon-fibre roof panel; wide front and rear arches; revised front and rear bumpers with functional cooling; stripped interior with fixed-back bucket seats and no rear parcel shelf. Uprated 5.4-litre M113 V8 producing approximately 400 bhp, retuned exhaust and revised final drive. Motorsport-derived suspension, larger brakes and bespoke lightweight wheels. The only Black Series built on the SLK platform.
Value premium
Approximately 4–6× a comparable R171 SLK 55 AMG in equivalent condition; the strongest cars now trade well into six figures in USD and clear £200,000 in the UK.
Inspection points
Confirm original fixed roof, factory wide-arch panels and Black Series-specific bumpers are unrepaired and original paint. Verify AMG service history; check for M113 secondary-air pump and camshaft magneto history. Confirm bucket seats, harness bar and Black Series-specific interior trim are all present and correct.
Authentication
Verify VIN against the Mercedes-Benz build record via a Mercedes-AMG dealer data card. Genuine Black Series cars carry unique interior badging, an AMG plaque referencing Black Series build, and specific option codes on the data card. Several wide-body kit conversions of standard SLK 55s exist and should be priced strictly as standard cars.

Production figures sourced from official marque records and specialist registers. Verify chassis documentation with the relevant marque register before purchase.

Buyer's Guide

What to look for

Provenance and originality

Start with identity, paperwork and originality. For the Mercedes-Benz SLK 55 AMG, the strongest cars have continuous ownership history, matching numbers where applicable, original books and tools, factory build documentation and evidence of work by manufacturer-approved specialists. Original paint, low-owner history, full Mercedes-AMG or approved-specialist service records, and — for the R172 — a factory Handling Package are the strongest levers.

Mechanical inspection priorities

M113 (R171) is robust but a cam-magneto sensor, secondary-air pump and SBC electro-hydraulic brake actuator are recurring items. M152 (R172) is a fundamentally sound naturally aspirated M157 derivative — check for smooth cylinder-deactivation transitions and 7G-Tronic fluid history. A proper pre-purchase inspection includes cold-start behaviour, ECU diagnostics and fault-code history (where applicable), leak-down or compression testing, underbody photography, suspension and chassis inspection, brake condition and a long enough road test to expose heat-related faults. Deferred maintenance on a car of this class is almost always more expensive than buying a better-sorted example.

Body, paint and accident history

Use a paint-depth gauge, lift access and a specialist familiar with the model's factory panel gaps and finish standards. Collector value is dramatically affected by structural repairs, refinished panels, poor paintwork and missing factory trim or option content. Documented cosmetic refresh is acceptable; concealed accident or fire damage must be priced severely.

Specification strategy

Documented AMG service history, original paint, and — on the R171 — a clean SBC brake service record are the primary value drivers; R172 cars benefit from documented cylinder-deactivation behaviour and 7G-Tronic fluid service. Specification, colour, options and limited-build variants move values significantly. Buy the best-documented example in the most desirable specification you can justify, rather than a tired example of a rarer derivative that will need years of corrective work.

Pricing

What to pay

SLK 55 AMG Black Series (R171)
USD$170,000 – $260,000
GBP£130,000 – £200,000
EUR€150,000 – €230,000
Documented, original-specification cars are the strongest collector proposition and trade well clear of the standard SLK 55.
SLK 55 AMG R172 (2012–2015)
USD$40,000 – $65,000
GBP£30,000 – £48,000
EUR€34,000 – €55,000
Final naturally aspirated V8 SLK; low-mileage, well-optioned cars command the top of the range.
SLK 55 AMG R171 (excellent)
USD$28,000 – $42,000
GBP£20,000 – £32,000
EUR€23,000 – €36,000
Best-kept M113 cars with full AMG history and clean SBC record.
SLK 55 AMG R171 (good driver)
USD$16,000 – $26,000
GBP£12,000 – £19,000
EUR€14,000 – €22,000
Honest, useable cars — expect to budget for SBC and cosmetics.

Regional ranges authored independently — each reflects its local market, not an FX conversion

Ownership

Living with it

Typical mileage
1,000–4,000 miles typical for collector use
Service interval
12 months; mileage interval varies by model and use
Annual running cost
$6,000 – $20,000
Fuel economy
8–17 mpg depending on use
Insurance
Use an agreed-value collector or specialist supercar policy with limited mileage, secure storage, documented photography and an annual value review. Premiums vary sharply by age, storage location, declared value and driver profile.

Maintenance planning

Budget annually even if the car is used sparingly. Fluids age, tyres and date-coded rubber components must be replaced regardless of mileage, and stored cars need exercise. A documented maintenance rhythm protects both reliability and resale value.

Parts and specialist access

Mercedes-AMG main dealers and a small independent specialist network handle both generations; SBC and 7G-Tronic work require the correct AMG-level diagnostic tooling. Before purchase, confirm parts availability for model-specific bodywork, electronics, gearbox and engine components. A discounted car waiting on unobtainable parts or a factory service slot is rarely a saving in collector ownership.

Common Problems

Known issues by system

Brakes (R171)

SBC hydraulic brake unit failure

Critical$1,500 – $3,500
Symptoms — Brake warning message; hard pedal; reduced assistance.
Inspection — Confirm SBC operation and check for stored counter readings via STAR diagnostics.
Engine (M113)

Secondary air injection pump and check valves

Moderate$900 – $2,200
Symptoms — P0410 fault code; MIL after cold start.
Inspection — OBD scan; check valve condition on both banks.
Engine (M113)

Camshaft magneto (cam adjuster) sensors

Moderate$700 – $1,800
Symptoms — Rough running, misfire codes, occasional stall.
Inspection — Fault-code history and specialist inspection.
Roof

Vario folding hardtop hydraulics

Moderate$1,200 – $3,500
Symptoms — Slow or partial roof operation; fault codes.
Inspection — Cycle the roof multiple times cold and hot; scan for pump errors.
Transmission

7G-Tronic fluid service neglect

Moderate$450 – $900 (service); rebuilds significantly more.
Symptoms — Delayed shifts, harsh engagement.
Inspection — Confirm fluid and filter service every 40,000 miles.
Engine (M152)

Cylinder-deactivation solenoid faults

Moderate$800 – $1,800
Symptoms — Rough transition in and out of four-cylinder mode.
Inspection — STAR diagnostics; road test in cruise conditions.
Suspension

Front lower arm bush wear

Minor$600 – $1,200
Symptoms — Clunk over sharp bumps; steering vagueness.
Inspection — Lift inspection and steering check.
Valuation

Current value bands by region

Concours
USD
$60,000
GBP
£46,000
EUR
€52,000
▲ +3% 12-mo
Excellent
USD
$42,000
GBP
£32,000
EUR
€36,000
▲ +2% 12-mo
Good
USD
$26,000
GBP
£19,000
EUR
€22,000
▬ +1% 12-mo
Fair
USD
$16,000
GBP
£12,000
EUR
€14,000
▬ 0% 12-mo
Project
USD
$9,000
GBP
£7,000
EUR
€8,000
▼ -2% 12-mo

Each region quoted in its local currency — independent market readings, not FX conversions

R172 SLK 55 AMG values have been firming since 2024 as the market recognises it as the last naturally aspirated V8 SLK. R171 cars remain broadly affordable but the best-documented, low-owner examples with clean SBC records are pulling clear of tired cars. The Black Series has re-rated significantly and now trades in a separate collector market.

Auctions

Recent results

DateAuctionCarMileageResult
2025-06-07
Bring a Trailer
Online
2013 SLK 55 AMG P30 (R172)
Verified: bringatrailer.com/listing/2013-mercedes-benz-slk55-amg-8/ — listing title '28k-Mile 2013 Mercedes-Benz SLK55 AMG P30'; sold 06/07/2025.
28,000 mi
$37,500
Sold
2025-05-28
Bring a Trailer
Online
2006 SLK 55 AMG P30 Performance Package (R171)
Verified: bringatrailer.com/listing/2006-mercedes-benz-slk55-amg-31/ — listing title '8k-Mile 2006 Mercedes-Benz SLK55 AMG P30 Performance Package'; seller describes 'Specificed with AMG Performance Package … clean Carfax report'; sold 5/28/25.
8,000 mi
$38,000
Sold
2025-04-24
Bring a Trailer
Online
2009 SLK 55 AMG (R171 facelift)
Verified: bringatrailer.com/listing/2009-mercedes-benz-slk55-amg-7/ — listing title '7k-Mile 2009 Mercedes-Benz SLK55 AMG'; sold 04/24/2025.
7,000 mi
$41,000
Sold
Investment

Long-term outlook

EmergingHorizon: 5–10 years

R172 as the last naturally aspirated V8 SLK is the clearest collector case; R171 cars follow as the closing chapter of the M113 V8. Black Series is already established and trades independently. Risks are running costs on tired cars and the SBC service liability on early R171s.

Recommended

The trusted network

Specialists

  • Mercedes-Benz factory-approved specialist
    View →
    UK / Europe
    Mercedes-Benz SLK 55 AMG inspections, major service planning and originality reviews.
  • Model-focused independent
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    United States
    Pre-purchase inspections, scheduled service and market-correct preparation for the SLK 55 AMG.
  • Concours preparation studio
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    International
    Paint correction, PPF, detailing, preservation and sale preparation for premium collector cars.
  • Hagerty
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    USA / UK / EU
    Agreed-value collector and supercar insurance with global recognition.
  • Lockton Performance
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    UK / EU
    Specialist agreed-value cover for modern hypercars and limited-production supercars.

Storage

  • Windrush Car Storage
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    Cotswolds, UK
    Climate-controlled storage and collection management for high-value classic and supercars.
  • Autovault
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    Bicester, UK
    Secure climate-controlled storage at Bicester Heritage with inspection programmes.
  • Classic Car Club Manhattan
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    New York, NY
    Secure urban storage for collector and modern performance cars.

Transport

  • CARS UK
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    UK & Europe
    Enclosed event, concours and collection transport across Europe.
  • Reliable Carriers
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    USA (national)
    Enclosed coast-to-coast transport for premium supercars and classics.
  • FERRLOG
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    Italy / Europe
    Air-ride enclosed transport for Italian and European collector cars.

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The valuation figures in this guide are for research purposes only and do not constitute financial or investment advice. See our full disclaimer.